Electronic assembly having a removable power supply

ABSTRACT

An electronic device includes a first chassis, a second chassis, and at least one flexible circuit extending therebetween. The first chassis is oriented along a first axis and comprises at least one first microprocessor. The second chassis is oriented along a second axis and comprises at least one power generating component. The flexible circuit comprises a first end and a second end, wherein the first end is connectable to the first chassis and the second end is connectable to the second chassis. The first chassis is movable relative to the second chassis between a position wherein the first axis is substantially perpendicular to the second axis and a position wherein the first axis is substantially parallel to the second axis.

This application is a Continuation of U.S. Ser. No. 10/237,317 filedSep. 9, 2002, now U.S. Pat. No. 6,659,779.

BACKGROUND

The delivery of direct current (DC) power free of transients or otherfluctuations is crucial for the operation of many high performanceelectronic devices. Many of these electronic devices operate at veryhigh frequencies and are adversely affected by transients or otherfluctuations in their power supplies. Even small transients orfluctuations will adversely affect many electronic devices. For example,a slight voltage transient in a power supply of a high speed processormay cause data errors, such as a low voltage signal being registered orotherwise interpreted by the processor as a high voltage signal.

Power supplies are typically located on circuit boards that are separatefrom other components, such as processors, of the electronic devices.This separation provides for simplification of manufacturing in additionto isolating the power supplies from the other components of theelectronic devices. The power supplies and other components are able tobe manufactured at different locations and connected together at a latertime during final assembly. Likewise, either the power supplies or theother components may be repaired or retrofit without the need to repairor retrofit the other. In addition, the separation provides isolationbetween the power supplies and the other components and reduces theprobability that a transient generated in the power supply will be ableto affect the operation of the electronic devices.

The isolation, however, creates problems in delivering DC power that isfree of transients and other fluctuations to the components of theelectronic devices. For example, the conductors that are used totransfer power from the power supplies to the electronic deviceinherently have inductance and resistance. The inductance increases theprobability that a transient will occur on the power supply line, whichwill adversely affect the performance of the electronic device. Theresistance reduces the power that is supplied to the components of theelectronic device and increases the heat generated by the electronicdevice.

In many applications, a cable is connected between the power supply andthe electronic device. The flexibility of a cable typically enables thepower supply and the electronic device to be connected and disconnectedwith relative ease. Cables, however, typically have a higher impedance,which in turn makes them more likely to generate transients and voltagefluctuations. Therefore, cables present problems when used in many highspeed applications.

SUMMARY

An electronic device comprising a first chassis, a second chassis, andat least one flexible circuit extending therebetween is disclosed. Inone non-limiting embodiment, the first chassis is oriented along a firstaxis and comprises at least one first microprocessor. The second chassisis oriented along a second axis and comprises at least one powergenerating component connectable thereto. The flexible circuit extendsbetween the first chassis and the second chassis. The flexible circuitcomprises a first end and a second end, wherein the first end isconnectable to the first chassis and the second end is connectable tothe second chassis. The first chassis is movable relative to the secondchassis between a position wherein the first axis is substantiallyperpendicular to the second axis and a position wherein the first axisis substantially parallel to the second axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of an electronic device having a powerboard connectable to a processor board according to an embodiment of thepresent invention.

FIG. 2 is a top perspective view of an embodiment of the electronicdevice of FIG. 1 showing an arrangement between a processor board and apower board.

FIG. 3 is a top perspective view of an embodiment of the power board ofFIG. 1.

FIG. 4 is a side perspective view of an embodiment of a first flexiblecircuit of the electronic device of FIG. 1.

FIG. 5 is a top view of an embodiment of the connection between theflexible circuits and the power board of FIG. 1.

FIG. 6 is a side, cut away view of an embodiment of the flexible circuitand connector of the electronic device of FIG. 1.

FIG. 7 is a cut away view of and embodiment of the end of the flexiblecircuit of the electronic device of FIG. 6.

FIG. 8 is an electrical schematic diagram of an embodiment of one of theflexible circuits of FIG. 1.

FIG. 9 is a top view of an embodiment of the connection between theflexible circuits and the power board of FIG. 1.

FIG. 10 is a top view of an embodiment of the connection between theflexible circuits and the power board of FIG. 1.

DESCRIPTION

A non-limiting embodiment of an electronic device 100 is shown in FIG.1. The electronic device 100 may have a first chassis 110, sometimesreferred to herein as a processor board 110, and a second chassis 112,sometimes referred to herein as a power board 112. The processor board110 and the power board 112 are connectable to one another by one ormore flexible circuits. In the non-limiting embodiment described herein,a first flexible circuit 116 and a second flexible circuit 118 connectthe processor board 110 to the power board 112. The first flexiblecircuit 116 and the second flexible circuit 118 are able to transferpower between the power board 112 and the processor board 110 whilebeing flexed or bent in a manner similar to a ribbon-type data cable.

Spatial reference axes are used herein to describe the locations andorientations of the components of the electronic device 100 relative toone another. For illustration purpose, the spatial reference axes arefixed relative to the power board 112. The spatial reference axes arereferred to as the x-axis, the y-axis, and the z-axis, and all areorthogonal to one another. In addition to the spatial reference axesdescribed above, other reference axis are used herein to described thelocations of the processor board 110 and the power board 112 relative toone another. As shown in FIG. 1, the processor board 110 extends or isoriented along an axis AA and the power board 112 extends or is orientedalong an axis BB. In the configuration of the electronic device 100shown in FIG. 1, the axis AA and the axis BB are substantially parallel.In other configurations of the electronic device 100, the axis AA andthe axis BB may be at other angles relative to one another. It should benoted that the axis BB is substantially parallel to the x-axis.

FIG. 2 is a top perspective view of the electronic device 100 shown in adifferent configuration and described in greater detail below. Theprocessor board 110 may have plurality of microprocessors 122 and theiraccompanying electronic components 123 located thereon. The non-limitingembodiment of the processor board 110 described herein has twomicroprocessors, which are referred to as a first microprocessor 124 anda second microprocessor 126. It should be noted that any number ofmicroprocessors 122 and electronic components 123 may be located on theprocessor board 110. The processor board 110 serves to process data andthe power board 112 serves to supply power to the processor board 110.It should be noted that data may be transmitted through the power board112 by way of the first flexible circuit 116 and the second flexiblecircuit 118. In other embodiments of the electronic device 100, otherelectronic components, such as ASIC's, may be attached to the processorboard 110 in addition to or in place of the microprocessors 122.Accordingly, other embodiments of the processor board 110 may servefunctions other than processing data.

It should be noted that the axis AA and the axis BB are at differentangles relative to one another in the configuration of the electronicdevice 100 of FIG. 2 than they were in the configuration of theelectronic device 100 of FIG. 1. As described in greater detail below,the processor board 110 and the power board 112 may move relative toeach other, which changes the angle between the axis AA and the axis BB.The first flexible circuit 116 and the second flexible circuit 118function similar to hinges, which enable the processor board 110 and thepower board 112 to pivot relative to each other. As described in greaterdetail below, the movement of the processor board 110 relative to thepower board 112 enables them to be readily disconnected and reconnectedto one another. For example, when the electronic device 100 is in theembodiment shown in FIG. 2, the power board 112 may be readily connectedor disconnected from the first flexible circuit 116 and the secondflexible circuit 118.

In addition to the microprocessors 122 and the electronic components123, the processor board 110 may have a first tab 134 and a second tab136 extending therefrom. As shown in FIG. 2, the first tab 134 mayextend in a direction substantially parallel to the axis AA and thesecond tab 136 may extend in a direction substantially perpendicular tothe axis AA. As described in greater detail below, the tabs 134, 136serve to align the processor board 110 with the power board 112 when theprocessor board 110 and the power board 112 are located in closeproximity to one another as shown in FIG. 1. In addition to alignment,the tabs 134, 136 may also serve to secure the processor board 110 tothe 110 as described in greater detail below. It should be noted thatthe tabs 134, 136 are not necessarily a requirement of the processorboard 110. It should also be noted that the processor board 110 may havemore or less than two tabs extending in any number of directions.

A top perspective view of the electronic device 100 with the processorboard 110, FIG. 2, removed therefrom is shown in FIG. 3. With additionalreference to FIG. 2, the power board 112 may have power generatingcomponents 140 located thereon that serve to supply power to themicroprocessors 122 and electronic components 123 located on theprocessor board 110. The power generating components 140 may, asexamples, provide power or convert power to levels required for theoperation of the processor board 110.

The power board 112 may have a first slot 142 and a second slot 144located thereon or formed therein. The first slot 142 may be formed fromtwo extended portions 146 with a recessed portion or slot 148 locatedtherebetween. In the non-limiting example shown in FIG. 3, the recessedportion 148 extends in a direction substantially parallel to the axisBB. Accordingly, the first slot 142 is referred to herein as extendingin a direction substantially parallel to the axis BB. The second slot144 may have two extended portions 150 with a recessed portion 152located therebetween, wherein the recessed portion 152 extends in adirection substantially perpendicular to the axis BB. Accordingly, thefirst slot 142 is referred to herein as extending in a directionsubstantially perpendicular to the axis BB. The slots 142, 144 have beendescribed herein as being formed from the extended portions 146, 150respectively. In another embodiment of the power board 112, the slots142, 144 are formed by cutting or otherwise forming slots directly intothe power board 112.

With additional reference to FIG. 2, the slots 142, 144 serve to receivethe tabs 134, 136 when the processor board 110 and the power board 112are located adjacent one another as shown in FIG. 1. When the processorboard 110 is placed adjacent the power board 112, the first tab 134 isreceived into the first slot 142 and the second tab 136 is received intothe second slot 144. When this is accomplished, the processor board 110is prevented from significantly moving in either the x-direction or they-direction relative to the power board 112. Movement may be provided inthe z-direction in order to provide for tolerances between the processorboard 110 and the power board 112. For example, the tolerance in thez-direction may provide for height tolerances in the microprocessors122, the electronic components 123, and the power generating components140 located on the processor board 110 and the power board 112.

In one embodiment of the electronic device 100, the tabs 134, 136 andthe slots 142, 144 may have locking mechanisms or interference fits thatserve to secure the processor board 110 to the power board 112 when theyare in close proximity as shown in FIG. 1. The processor board 110 hasbeen described as having tabs 134, 136 and the power board 112 has beendescribed as having slots 142, 144. The tabs 134, 136 and slots 142, 144may be interchanged wherein the tabs 134, 136 are located on the powerboard 112 and the slots 142, 144 are located on the processor board 110.

FIG. 1 shows an embodiment of the connection between the first flexiblecircuit 116 and the second flexible circuit 118 to the power board 112.A first end 156 of the first flexible circuit 116 and a first end 158 ofthe second flexible circuit 118 are operatively or otherwiseelectrically and/or mechanically connected to the power board 112, i.e.,soldered. A side perspective view of the second flexible circuit 118separate from the processor board 110 and the power board 112 is shownin FIG. 4. In addition to the first end 158, the second flexible circuit118 has a second end 160, an upper edge 162, and a lower edge 164. Theabove-described ends and edges of the second flexible circuit 118 defineboundaries of a front side 168 of the second flexible circuit 118 A backside 170 is oppositely disposed relative to the front side 168.

The portion of the second flexible circuit 118 in the proximity of thefirst end 158 may be cut or otherwise split to form a plurality of tabs174. In the non-limiting embodiment of the second flexible circuit 118described herein, three tabs 174 are formed in the proximity of thefirst end 158. The tabs 174 are individually referred to as a first tab176, a second tab 178, and a third tab 180. The tabs 174 extend indirections substantially along the x-axis and may extend in alternatingdirections as shown in FIG. 4. In the non-limiting embodiment describedherein, the first tab 176 and the third tab 180 extend in a firstdirection substantially parallel to the x-axis. The second tab 178extends in a substantially opposite direction parallel to the x-axis.The first end 156 of the first flexible circuit 116, FIG. 1, may besubstantially similar to the first end 158 of the second flexiblecircuit 118 as shown in FIG. 4. Other embodiments of the first end 158of the second flexible circuit 118 are described below.

Referring to FIG. 5, which is a plan view showing the connection of thefirst flexible circuit 116 and the second flexible circuit 118 to thepower board 112, the tabs 174 serve to reinforce the connections betweenthe flexible circuits 116, 118 and the power board 112. The first tab176 and the second tab 178 of the second flexible circuit 118 arevisible in the view of FIG. 5. As shown in FIG. 5, the tabs 176, 178extend in opposite directions along the x-axis, which serves to maintaina first portion 182 of the second flexible circuit 118 in asubstantially fixed position relative to the power board 112. Theattachment of the second flexible circuit 118 to the power board 112also reduces the possibility that the second flexible circuit 118 willpeal or tear from the power board 112. The first portion 182 of thesecond flexible circuit 118 is the portion of the second flexiblecircuit 118 that is adjacent or otherwise in close proximity to thepower board 112. In the embodiment of the electronic device 100described herein, the first portion 182 extends along the z-axis and ismaintained in this position with little movement relative to the powerboard 112. The first flexible circuit 116 may also have a first portion184 that is substantially similar to the first portion 182 of the secondflexible circuit 118.

A bend 186 is located adjacent the first portion 182 of the secondflexible circuit 118. A bend 188 is located adjacent the first portion184 of the first flexible circuit 116. The bends 186, 188 serve as pivotpoints in the flexible circuits 116, 118. The pivot points enable theprocessor board 110 and the power board 112 to be moved relative to oneanother without being fully detached from one another. The bends 186,188 also serve to keep the first flexible circuit 116 and the secondflexible circuit 118 in fixed positions so that they do not interferewith other items located in the proximity of the electronic device 100.

The tabs 174 may have conductors, not shown in FIG. 5, that areelectrically and mechanically connected or connectable to conductors,not shown in FIG. 5, located within the power board 112. For example,conductors within the tabs 174 may be soldered to conductors within thepower board 112. It should be noted that the connection of the tabs 174to the power board 112 provides for the transfer of power and, in oneembodiment, data between the processor board 110 and the power board112.

Referring again to FIG. 4, a connector or socket 190 may be electricallyand mechanically connected to the second flexible circuit 118 in theproximity of the second end 160. The socket 190 may have a plurality ofconductors 192 extending therefrom that electrically connect toconductors, not shown in FIG. 4, located within the second flexiblecircuit 118. The conductors 192 serve to electrically and mechanicallyconnect to conductors, not shown in FIG. 4, on the power board 112FIG.1, which are connected to the second microprocessor 126.

A greatly enlarged side, cut away view of the second flexible circuit118 and the processor board 110 is shown in FIG. 6. The processor board110 and the second flexible circuit 118 are not connected in theillustration of FIG. 6. However, FIG. 6 clearly shows how they are to beconnected. The second flexible circuit 118 has a width W1 extendingbetween the front side 168 and the back side 170. In the non-limitingembodiment of the second flexible circuit 118 described herein, thewidth W1 is approximately 0.140 inches. The second flexible circuit 118has a first conductor, sometimes referred to herein as a power plane196, and a second conductor, sometimes referred to herein as a groundplane 198, located therein. The power plane 196 and the ground plane 198may be separated by a dielectric at a distance D1. In the non-limitingembodiment of the second flexible circuit 118 described herein, thedistance D1 may be approximately 1.8 to 2.2 mils. It should be notedthat the second flexible circuit 118 is described herein as only havingone power plane 196 and one ground plane 198. It is to be understoodthat the second flexible circuit 118, and the first flexible circuit116, FIG. 1, may have a plurality of power planes and ground planes. Theplurality of conductive planes may be arranged similar to the powerplane 196 and the ground plane 198 described herein.

A cut away view of the second end 160 of the second flexible circuit 118is shown in FIG. 7. It should be noted that FIG. 7 only shows thearrangement of the power plane 196 and the ground plane 198 and thatother conductors, not shown, may be located within the second flexiblecircuit 118. For example, other conductors that serve to transmit datamay be located within the second flexible circuit 118. Both the powerplane 196 and the ground plane 198 have thicknesses T. In thenon-limiting embodiment of the second flexible circuit 118, thethickness T is based on the power plane 196 and the ground plane 198being formed from two ounce to four ounce copper. In the non-limitingembodiment of the first flexible circuit 116 described herein, both thepower plane 196 and the ground plane 198 have the same width W2. In thenon-limiting embodiment of the first flexible circuit 116 describedherein, the width W2 is approximately 2.1 inches. It should be notedthat the power plane 196 is aligned with the ground plane 198 to formpower transmission line that is electrically similar to a parallel platecapacitor. In the embodiment described herein, the effective capacitancebetween the parallel plates is approximately 1.0 pf.

Referring again to FIG. 6, the conductors 192 on the socket 190 may behollow and may be adapted to receive conductors 200 located on theprocessor board 110. Thus, the processor board 110 may be connectable tothe second flexible circuit 118 and the power board 112. A plurality ofvias 204 may electrically connect the conductors 192 to the power plane196 and the ground plane 198. Accordingly, the conductors 192 serve toprovide power to the processor board 110 as is described in greaterdetail below. It should be noted that other conductors 192 in the socket190 may serve to connect to other conductive planes, not shown, in thesecond flexible circuit 118. For example, the other conductors 192 mayserve to transmit data to and from the processor board 110.

As described above, the processor board 110 has a plurality ofconductors 200 located thereon. The conductors 200 are connected by aplurality of vias 206 to conductors 208 that are associated with thesecond microprocessor 126. In one embodiment, the second microprocessor126 is soldered to the processor board 110 and the conductors 208 aresolder pads. In another embodiment, the second microprocessor 126 isconnected to the processor board 110 by the use of a socket.Accordingly, in this embodiment, the conductors 208 represent bothsockets on the processor board 110 and pins on the second microprocessor126.

The processor board 110 of FIG. 6 has a capacitor 210 located thereon,which is representative of one of a plurality of capacitors and othercomponents that may be connected to the processor board 110. As shown inFIG. 6, the capacitor 210 is connected to the vias 206, which connectthe capacitor 210 to the power plane 196 and ground plane 198 when theprocessor board 110 is connected to the second flexible circuit 118. Thecapacitor 210 serves to attenuate transients and other voltagefluctuations between the power plane 196 and the ground plane 198.

As shown in FIG. 6, the conductors 208 are connected directly to vias206, which connect to the second flexible circuit 118. Thus, few longconductive lands or traces are required to be located on the processorboard 110. More specifically, the vias 206 may connect the conductors208 to the second flexible circuit 118 without the need for long landsor traces. The lack of long conductive lands further reduces theinductance associated with the delivery of power to the secondmicroprocessor 126. It should be noted that small conductive lines 212may connect the capacitor 210 to the vias 206. The capacitor 210 may belocated in close proximity to the vias 206 that supply power to thesecond microprocessor 126. Therefore, the lines 212 may be very shortand may be formed of half ounce copper. The lines 212 may be shortenough so as not to have any significant affect on the inductance of theprocessor board 110.

Having described the physical properties of the electronic device 100,FIG. 1, the operating properties of the electronic device 100 will nowbe described.

Referring again to FIG. 1, the first flexible circuit 116 and the secondflexible circuit 118 serve to electrically connect the processor board110 to the power board 112. The flexible circuits 116, 118 may alsoserve to mechanically connect the processor board 110 to the power board112. As described in greater detail below, the flexible circuits 116,118 provide a low resistance and low inductance power transfer meansbetween the power board 112 and the processor board 110. The lowinductance serves to reduce or attenuate transients and other voltagefluctuations on the power supply lines between the power board 112 andthe processor board 110. The inductance and resistance may be reduced toan extent that the amount of decoupling capacitance between the powerboard 112 and the processor board 110 is significantly reduced relativeto cable-type connectors. The reduced decoupling capacitance reduces thecosts and increases the reliability of the electronic device 100. Itshould be noted that the inductance and resistance may be reduced so lowthat they may actually be considered to be characteristics of the powerboard 112 and not the first and second flexible circuits 116, 118.

By replacing a conventional cable-type connector with the first flexiblecircuit 116 and the second flexible circuit 118, the inductance betweenthe processor board 110 and the power board 112 is minimized. Becausethe second flexible circuit 118 is a flexible, circuit having parallelplane conductors, the inductance between the planes is governed by theequation: $L \approx \frac{\mu_{o}\mu_{r}D\quad 1}{W\quad 2}$

With additional reference to FIGS. 6 and 7, assuming that the distanceD1 is approximately 2.0 mils, the width W2 is approximately 2.1 inches,and μ₀ and μ_(r) are permeability constants, the inductance between thepower plane 196 and the ground plane 198 is approximately 30.4 pH/inch.The same calculations apply to the conductive planes, not shown, in thefirst flexible circuit 116. Assuming that the first and second flexiblecircuits 116, 118 are between two and five inches long, the minimuminductance is approximately 61.0 picohenries and the maximum inductanceis approximately 152.0 picohenries. This inductance is approximatelyforty percent of the inductance associated with a connector that usescables.

In addition to a minimal inductance, the resistance is also reducedassociated with the power plane 196 and the ground plane 198 is alsominimized. Using the square counting technique to calculate resistance,a flexible circuit that is five inches long has approximately 2.5 twoinch squares. A flexible circuit as described herein that is two incheslong and 2.1 inches wide has approximately one two inch square. Assumingthat the power plane 196 and the ground plane 198 are made of four ouncecopper, they are approximately 4.0 mils thick and have a resistance ofapproximately 0.121 milliohms per square. Therefore, a flexible circuitthat is two inches long has a resistance of approximately 0.121milliohms and a flexible circuit that is five inches long has aresistance of approximately 0.302 milliohms. It should be noted thatother circuit configurations may have planes that are approximately 2.0mils thick and formed from two ounce copper.

The aforementioned minimal resistance and inductance reduces thetransients on the power plane 196 relative to the ground plane 198. Itfollows that noise on the power plane 196 is also reduced. The noise orchange in voltage ΔV is governed by the equation:

ΔV=L di/dt+IR

When the aforementioned equation is applied to a five inch flexiblecircuit having an inductance of approximately 152.0 picohenries and aresistance of approximately 0.302 milliohms, the noise is approximately37.85 millivolts. This noise is a 65% reduction over noise associatedwith a connector using cables. In addition to the noise and transientreduction, the minimal resistance of the flexible circuits 116, 118reduces the heat associated with the electronic device, which reducesthe cooling equipment and the like that is required to cool theelectronic device 100.

An electrical schematic of an embodiment of the second flexible circuit118 being approximately two inches long is shown in FIG. 8. Theschematic of FIG. 8 assumes that an inductance of approximately 40.0 nHexists on the output of the power board. As shown in FIG. 8, theflexible cable has an inductance of approximately 61.0 pH and aresistance of approximately 0.1 milliohms. Because the inductance of theflexible cable is between a factor of two and three lower than theinductance of the output impedance, the inductance of the flexible cableis negligible. Accordingly, the inductance of the flexible circuit maybe disregarded and a coupling capacitance of only 0.5 uf may beprovided.

A cable-type connector does not have the electrical characteristics ofthe flexible cable. For example, a cable-type connector may have aninductance of approximately four hundred picofarads, which issignificant relative to the output impedance of a power supply. Inaddition, the resistance is typically about 0.7 milliohms. Such acable-type connector may require several millifarads of couplingcapacitance and will have inferior performance.

Having described the electrical characteristics of the electronic device100, the operational characteristics will now be described.

In addition to reducing transients on the power board 112 and theprocessor board 110, the electronic device 100 provides for the easyinstallation and removal of the processor board 110 to and from thepower board 112. As described above, the processor board 110 isconnectable to the first and second flexible circuits 116, 118.Accordingly, the processor board 110 is connectable to the power board112. With additional reference to FIG. 2, the processor board 110 isconnectable to the power board 112 by connecting the connector 190 onthe second flexible circuit 118 and a similar connector on the firstflexible circuit 116 to the microprocessors 122. As shown in FIG. 2, theprocessor board 110 may be readily connected and disconnected to andfrom the first and second flexible circuits 116, 118 when the axis AA issubstantially perpendicular to the axis BB.

After the processor board 110 is connected to the power board 112, theprocessor board 110 may be moved to a position where it is proximate thepower board 112 as shown in FIG. 1. More specifically, the processorboard 112 may pivot on the bends 186, 188, FIG. 5, in the first andsecond flexible circuits 116, 118 to a point where the axis AA issubstantially parallel to the axis BB. The first tab 134, FIG. 2, maythen be received by the first slot 142. Accordingly, the second tab 136may be received by the second slot 144. This reduces the movement of theprocessor board 110 in both the x-direction and the y-direction relativeto the power board 112. Mechanisms, not shown, may be provided to lockor secure the tabs 134, 136 into the slots 142, 144. For example, theslots 142, 144 may form interference fits with the tabs 134, 136.

The connectability of the processor board 110 to the power board isuseful when the electronic device 100 is located in a larger chassis,not shown. For example, the power board 112 may be secured to thechassis. The processor board 110 may then be mechanically andelectrically connected to the power board 112 as described above. Shouldone of the mircoprocessors 122 need replacement, the processor board 110as a whole may be readily replaced without removal of the power board112.

Having described some embodiments of the electronic device 100, otherembodiments will now be described.

Referring to FIG. 1, the electronic device 100 was described above withthe first flexible circuit 116 and the second flexible circuit 118connected to different microprocessors 122 on the processor board 110.It should be noted that the first flexible circuit 116 and the secondflexible circuit 118 may be replaced with a single flexible circuit thatconnects to all the microprocessors 122 on the processor board 110.

Referring to FIG. 2, the electronic device 100 has been described hereinwith the tabs 134, 136 located on the processor board 110 and the slots142, 144 located on the power board 112. In one embodiment of theelectronic device 100, the tabs are located on the power board 112 andthe slots are located on the processor board 110.

Referring to FIG. 5, the first flexible circuit 116 and the secondflexible circuit 118 have been shown having tabs 174 formed thereon thatconnect to the power board 112. Another embodiment of the connection ofthe first flexible circuit 116 and the second flexible circuit 118 tothe power board 112 is shown in FIG. 9. In the embodiment of FIG. 9, thefirst portion 182 of the second flexible circuit 118 is split into afirst half 220 and a second half 222. The first half 220 may, as anexample, have the power plane 196, FIG. 6, and the second half 222 may,as an example, have the ground plane 198, FIG. 2.

FIG. 10 shows another embodiment of the connection of the first flexiblecircuit 116 and the second flexible circuit 118 to the power board 112.In the embodiment of FIG. 10, the first portion 182 of the secondflexible circuit 118 and the first portion 184 of the first flexiblecircuit 116 are bend so a portion of each is connected to the powerboard 112.

While an illustrative and presently preferred embodiment of theinvention has been described in detail herein, it is to be understoodthat the inventive concepts may be otherwise variously embodied andemployed and that the appended claims are intended to be construed toinclude such variations except insofar as limited by the prior art.

What is claimed is:
 1. An electronic device comprising: a first chassisoriented along a first axis, said first chassis comprising at least onefirst microprocessor; a second chassis oriented along a second axis,said second chassis comprising at least one power generating componentconnectable thereto; and at least one first flexible circuit extendingbetween said first chassis and said second chassis, said at least onefirst flexible circuit comprising a first flexible circuit first end anda first flexible circuit second end, said first flexible circuit firstend being connectable to said first chassis, said first flexible circuitsecond end being connectable to said second chassis; said first chassisbeing movable relative to said second chassis between at least aposition wherein said first axis is substantially perpendicular to saidsecond axis and a position wherein said first axis is substantiallyparallel to said second axis.
 2. The electronic device of claim 1,wherein said first flexible circuit first end has a first connectorattached thereto, said first connector being connectable to said atleast one first microprocessor.
 3. The electronic device of claim 1,wherein said first flexible circuit second end comprises at least onefirst tab and at least one second tab, said at least one first tab beingconnected to said second chassis and extending in a first directionalong said second axis, said at least one second tab being connected tosaid second chassis and extending in a second direction along saidsecond axis, said first direction being opposite said second direction.4. The electronic device of claim 1, wherein said first chassis furthercomprises at least one second microprocessor.
 5. The electronic deviceof claim 4, wherein said at least one first flexible circuit isconnectable to said at least one second microprocessor.
 6. Theelectronic device of claim 4 and further comprising at least one secondflexible circuit connectable between said at least one secondmicroprocessor and said second chassis.
 7. The electronic device ofclaim 1, wherein the distance between said first flexible circuit firstend and said first flexible circuit second end is between about two andabout five inches.
 8. The electronic device of claim 1, wherein said atleast one first flexible circuit comprises at least one first conductiveplane and at least one second conductive plane extending between saidfirst flexible circuit first end and said first flexible circuit secondend, and at least one first conductive plane having a first surface,said at least one second conductive plane having a second surface, saidfirst surface facing said second surface.
 9. The electronic device ofclaim 8, wherein said at least one first conductive plane has a widthextending substantially perpendicular to an axis extending between saidfirst flexible circuit first end and said first flexible circuit secondend, said width being about 2.1 inches.
 10. The electronic device ofclaim 8, wherein said at least one first conductive plane has athickness of about 2.0 to about 4.0 mils.
 11. The electronic device ofclaim 8, wherein said at least one first conductive plane has athickness of about 4.0 mils.
 12. The electronic device of claim 8,wherein the distance between said first surface and said second surfaceis about 1.8 to about 2.2 mils.
 13. The electronic device of claim 8,wherein the distance between said fist surface and said second surfaceis about 2.2 mils.
 14. The electronic device of claim 8, wherein theinductance between said first conductor and said second conductor isbetween about 61 picohenries and about 152 picohenries.
 15. Theelectronic device of claim 8, wherein the inductance between said firstconductor and said second conductor is about 61 picohenries.
 16. Theelectronic device of claim 8, wherein the inductance between said firstconductor and said second conductor is about 30.4 picohenries per inchas measured between said first flexible circuit first end and said firstflexible circuit second end.
 17. The electronic device of claim 8,wherein the resistance of said first conductor between said firstflexible circuit first end and said first flexible circuit second end isbetween about 0.121 milliohms and about 0.302 milliohms.
 18. Theelectronic device of claim 8, wherein the resistance of said firstconductor between said first flexible circuit first end and said firstflexible circuit second end is about 0.121 milliohms.
 19. The electronicdevice of claim 1, wherein said first chassis further comprises at leastone tab extending therefrom, said second chassis further comprising atleast one slot located thereon, said at least one tab being receivablein said at least one slot.
 20. The electronic device of claim 1, whereinsaid first chassis comprises a first tab extending therefrom, said firsttab extending substantially parallel to said first axis, said secondchassis having a first slot located thereon, said first slot extendingsubstantially parallel to said second axis, said first tab beingreceivable by said first slot.
 21. The electronic device of claim 20,wherein said first chassis further comprises a second tab extendingtherefrom, said second tab extending substantially perpendicular to saidfirst axis, said second chassis further comprising a second slot locatedthereon, said second slot extending substantially perpendicular to saidsecond axis, said second tab being receivable in said second slot. 22.The electronic device of claim 1, wherein said second chassis furthercomprises at least one tab extending therefrom, said first chassisfurther comprising at least one slot located thereon, said at least onetab being receivable in said at least one slot.
 23. The electronicdevice of claim 1, wherein said second chassis comprises a first tabextending therefrom, said first tab extending substantially parallel tosaid second axis, said first chassis having a first slot locatedthereon, said first slot extending substantially parallel to said firstaxis, said first tab being receivable by said first slot.
 24. Theelectronic device of claim 23, wherein said second chassis furthercomprises a second tab extending therefrom, said second tab extendingsubstantially perpendicular to said second axis, said first chassisfurther comprising a second slot located thereon, said second slotextending substantially perpendicular to said first axis, said secondtab being receivable in said second slot.
 25. The electronic device ofclaim 1 and further comprising at least one second flexible circuitextending between said first chassis and said second chassis, said atleast one second flexible circuit comprising a second flexible circuitfirst end and a second flexible circuit second end, said second flexiblecircuit first end being connectable to said first chassis, and saidsecond flexible circuit second end being connectable to said secondchassis.
 26. The electronic device of claim 25, wherein said at leastone first flexible circuit comprises a first flexible circuit surface,wherein said at least one second flexible circuit comprises a secondflexible circuit surface, and wherein said first flexible circuitsurface substantially faces said second flexible circuit surface.